In the circumstances where a merchant or other business person wishes to display a message through a glass door or wall or other transparent surface, it is sometimes desirable to have a sign that displays identical or compatible messages on both sides of the sign. Moreover, it is sometimes desirable to have a sign that can be changed so as to display alternate messages. For example, a double face, changeable sign is desirable to indicate that a store is "open" or "closed". Such signs might be applied to the glass entrance door of a retail store.
It would be desirable to have a double face, changeable sign that exhibits the same or compatible messages on both faces of the sign, but which can be changed so as to exhibit alternate but compatible messages on both of its faces. For example, a double face, changeable sign might include the message "Open" to be exhibited through the glass entrance door to the outside of a retail store, while the inside surface of the sign might exhibit the compatible message "Thanks, call again." When the store is to be closed, the merchant can change the sign so that it displays through the glass to the outside of the store the message "Closed", and to the inside: "Cut off lights before leaving." In some instances the message exhibited to both sides of the sign might be identical.